Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in JAVA):

Solution:
import java.io.IOException;
import java.io.FilterInputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.BufferedInputStream;
import java.util.HashSet;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Zyflair Griffane
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		JoltyScanner in = new JoltyScanner(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		Letters solver = new Letters();
		solver.solve(1, in, out);
		out.close();
	}
}

class Letters {
    public void solve(int testNumber, JoltyScanner in, PrintWriter out) {
        HashSet<Character> set = new HashSet<>();
        for (char c: in.nextLine().replaceAll("[^a-z]", "").toCharArray()) {
            set.add(c);
        }
        out.println(set.size());
    }
}

class JoltyScanner {
    public static final int BUFFER_SIZE = 1 << 16;
    public static final char NULL_CHAR = (char) -1;

    StringBuilder str = new StringBuilder();
    byte[] buffer = new byte[BUFFER_SIZE];
    boolean EOF_FLAG = false;
    int bufferIdx = 0, size = 0;
    char c = (char) -1;
    BufferedInputStream in = new BufferedInputStream(System.in, BUFFER_SIZE);
    public JoltyScanner(InputStream in) {
        this.in = new BufferedInputStream(in);
    }

    public String nextLine() {
        if (EOF_FLAG) {
            throw new RuntimeException("EOF");
        }
        str.setLength(0);
        if (c == NULL_CHAR) {
            c = nextChar();
        }
        while (!EOF_FLAG && c != '\n') {
            str.append(c);
            c = nextChar();
        }
        c = NULL_CHAR;
        return str.toString();
    }

    public char nextChar() {
        if (EOF_FLAG) {
            return NULL_CHAR;
        }
        while (bufferIdx == size) {
            try {
                size = in.read(buffer);
                if (size == -1) {
                    throw new Exception();
                }
            }
            catch (Exception e) {
                EOF_FLAG = true;
                return (char) -1;
            }
            if (size == -1) {
                size = BUFFER_SIZE;
            }
            bufferIdx = 0;
        }
        return (char) buffer[bufferIdx++];
    }

}